1. Field of the Invention
The present invention is directed to a system for determining an acoustic sound level interior or exterior to an enclosed structure.
2. Description of the Prior Art
It is known that an interior pressure of a pressurized container can be calculated from measuring the displacement of a surface of the container. U.S. Pat. No. 3,882,718 to Kriebel teaches the application of this technique to pressure measurement in an eyeball to test for glaucoma.
It is also known that fiber optic interferometry can be used to sense the acceleration of fluid waves, as taught by U.S. Pat. No. 4,799,752 to Carome. It is further known that a grid of optical fibers can detect a distribution of strain on the grid, as taught by U.S. Pat. No. 4,781,056 to Noel et al.
However, heretofore there has been no system capable of obtaining a detailed mapping, or even an accurate single point or regional measurement, of the acoustic field in a fluid space exterior/interior to an enclosure based only on a condition, such as structural strain levels, of the structure itself.